Activities of Hypoxanthine-Guanine Phosphoribosyltransferase and Adenine Phosphoribosyltransferase in Erythrocytes from Patients with Down's Syndrome
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چکیده
منابع مشابه
Hypoxanthine-Guanine Phosphoribosyltransferase Variant
A B S T R A C T We have previously described a 14-yrold boy with hyperuricemia, renal failure, and accelerated purine production resistant in vivo and in vitro to purine analogs. This patient demonstrated normal red cell hypoxanthine-guanine phosphoribosyltransferase (HPRT) heat stability, electrophoresis at high pH, and activity at standard substrate levels. In the present report an abnormal H...
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A mutant form of human hypoxanthine-guanine phosphoribosyltransferase (HPRTToronto) was isolated from erythrocytes of a male patient with gout due to a partial deficiency of enzyme activity. The tryptic peptides of HPRTToronto were mapped by reverse-phase high pressure liquid chromatography in an attempt to define the precise abnormality in its primary structure. Sequence analysis of the single...
متن کاملChinese Hamster Hypoxanthine-Guanine Phosphoribosyltransferase
Hypoxanthine-guanine phosphoribosyltransferase from Chinese hamster brain, liver, and V79 tissue culture cells appears to have identical structural and catalytic properties. The enzyme has been purified 540-fold to apparent homogeneity from Chinese hamster brain. The native molecular weight is 78,000 to 85,000 determined by Sephadex G-100 column chromatography and acrylamide gel electrophoresis...
متن کاملHypoxanthine-guanine phosphoribosyltransferase: characteristics of the mutant enzyme in erythrocytes from patients with the Lesch-Nyhan syndrome.
The Lesch-Nyhan syndrome is characterized clinically by choreoathetosis, spasticity, selfmutilation, and mental and growth retardation. Biochemically, there is a striking reduction of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity in affected individuals. We have examined erythrocytes from 14 patients with the Lesch-Nyhan syndrome for the presence of hypoxanthine-guanine phosph...
متن کاملKinetic studies of hypoxanthine-guanine phosphoribosyltransferase.
The mechanism of reaction of human erythrocyte hypoxanthine-guanine phosphoribosyltransferase was investigated by initial velocity, product inhibition, and isotope exchange studies. Although initial velocity data are compatible with a mechanism involving binary enzyme-substrate complexes, the product inhibition and isotope exchange studies indicate that the reaction is ordered with the formatio...
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ژورنال
عنوان ژورنال: The Tohoku Journal of Experimental Medicine
سال: 1972
ISSN: 0040-8727,1349-3329
DOI: 10.1620/tjem.108.197